RadComboBox lose items on PostBack

4 posts, 0 answers
  1. Jesus
    Jesus avatar
    1 posts
    Member since:
    Jul 2009

    Posted 26 Jul 2013 Link to this post

    Hi,

    Here is the situation: I have a RadComboBox (not LoadOnDeman) which is filled with values when I load the page:

    <telerik:RadComboBox ID="drpCollectingScript" runat="server" Height="150px" Width="225px"
    DropDownWidth="360px" HighlightTemplatedItems="true" Filter="Contains" AutoPostBack="False"
    MarkFirstMatch="true" OnClientKeyPressing="setHighlightedItem"
    OnClientBlur="setId" OnClientFocus="toggleRadCombo" ViewStateMode="Enabled">
      <HeaderTemplate>
        <table style="width: 340px" cellspacing="0" cellpadding="0">
          <tr>
            <td style="width: 340px;">
              <asp:Label ID="lblCSCode" runat="server">Code</asp:Label>
            </td>
          </tr>
        </table>
      </HeaderTemplate>
      <ItemTemplate>
        <table style="width: 340px" cellspacing="0" cellpadding="0">
          <tr>
            <td style="width: 340px;">
              <%# DataBinder.Eval(Container, "Attributes['Code']")%>
            </td>
          </tr>
        </table>
      </ItemTemplate>
    </telerik:RadComboBox>

    CodeBehind:

    If Me.IsPostBack = False Then
      Dim scripts = New CatalogService().GetAllScriptTips()
      For i As Integer = 0 To scripts.Count - 1
        Dim item As New RadComboBoxItem()
        item.Text = scripts(i).Code
        item.Value = scripts(i).ScriptTipId
     
        item.Attributes.Add("Code", scripts(i).Code)
        item.Attributes.Add("Script", scripts(i).ContentDesign)
        drpCollectingScript.Items.Add(item)
        item.DataBind()
      Next
    End If

    The problem is that if I don't make a Postback that refreshes the table element in which the RadComboBox is contained (using RadAjaxManager) within aproximately 2 minutes after loading the page, then the RadComboBox loses all of its items and this problem extends aswell to the asp:DropDownList controls which are contained within the same table element.

    So, what's the problem here? What can I do to solve this problem?
  2. Nencho
    Admin
    Nencho avatar
    1458 posts

    Posted 31 Jul 2013 Link to this post

    Hello Arturo,

    I tried to replicate the described issue, but to no avail. I had prepared a sample page for you, demonstrating the behavior at my end. Would you give it a try at your end and let me know if I had missed something. Please find the attachment.

    Regards,
    Nencho
    Telerik
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  4. Jacob
    Jacob avatar
    1 posts
    Member since:
    Nov 2014

    Posted 05 Aug 2015 in reply to Nencho Link to this post

    I'm having exactly the same issue that I can consistently reproduce.

     I looked at your code...

    Can you please explain this line: item.DataBind()?

     Are you calling DataBind() method on RadComboBoxItem?

  5. Ivan Danchev
    Admin
    Ivan Danchev avatar
    837 posts

    Posted 10 Aug 2015 Link to this post

    Hello Arturo,

    The DataBind() method is called on the RadComboBoxItems so that the Template can use the custom attributes in its data-binding expressions. 

    Were you able to reproduce the issue in the sample project my colleague Nencho attached in his previous reply? If you were, could you please post your modifications so we can further investigate the reason for the observed behavior?

    Regards,
    Ivan Danchev
    Telerik
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